Visualization and quantification of vesicle trafficking on a three-dimensional cytoskeleton network in living cells

Recent progress in biology and microscopy has made it possible to acquire multidimensional data on rapid cellular activities. Unfortunately, the data analysis needed to describe the observed biological process still remains a major bottleneck. We here present a novel method of studying membrane trafficking by monitoring vesicular structures moving along a three-dimensional cytoskeleton network. It allows the dynamics of such structures to be qualitatively and quantitatively investigated. Our tracking method uses kymogram analysis to extract the consistent part of the temporal information and to allow the meaningful representation of vesicle dynamics. A fully automatic extension of this method, together with a statistical tool for dynamic comparisons, allows the precise analysis and comparison of overall speed distributions and directions. It can handle typical complex situations, such as a dense set of vesicles moving at various velocities, fusing and dissociating with each other or with other cell compartments. The overall approach has been characterized and validated on synthetic data. We chose the Rab6A protein, a GTPase involved in the regulation of intracellular membrane trafficking, as a molecular model. The application of our method to GFP-Rab6A stable cells acquired using fast four-dimensional deconvolution video-microscopy gives considerable cellular dynamic information unreachable using other techniques.     

THE DISTRICT OF COLUMBIA EDUCATIONAL TAX CREDIT ISSUE: A RESEARCH NOTE

This research note examines a recent tax credit initiative held in The District of Columbia. At issue was a tax credit of $1,200 per family for each child enrolled in a private school. Thus, parents, or guardians with children enrolled in private schools, stood to receive significant lax reductions. This referendum, if successful, would have had dramatic effects on the tax resources available to the District of Columbia and had a profound impact on public services, especially the schools. The effects of the tax credit initiative outcome would have extended beyond the District. Not only was the DC initiative part of a national tax revolt, it was also visibly located in the nation's capital. Depending on the outcome, the results would have encouraged either supporters or opponents of similar tax protest issues across the country. This paper analyzes the result by examining factors associated with voting. This note also offers some observations on tax issue campaigning and its relationship to influencing voters. Special attention will be addressed to the conception of voter's self-interest in deciding whether to support or oppose the tax credit issue. In this regard, it will be argued that voter altitudes toward self-interest, particularly “public regarding” attitudes, are good indicators for explaining the vote.     

爱“生活”从SKECHERS开始

生活是什么？一些创造者说：生活就是不断地创新,而我们每天都在这种不断的创新中追逐着,追逐奢侈品、追逐潮流、追逐新品,然而这些究竟是不是你最爱的事情呢？这些难道就是你生活的全部吗？除了讲得头头是道的各大品牌信息以外,静下心来考虑一下,你的梦想、希望呢？因为创造者还说过：生活分为“物质生活”与“精神生活”,我们却往往因为注重了“物质生活”而忽略了“精神生活”。     

玩过界—ADIDAS PRO LUX NBA

现在的adidas潮流鞋放到几年或几十年前基本上都与篮球运动有密切的关系,就拿Superstar来说,它原本专为篮球运动而设计,与生活时尚并无关系,但是经过日后的改良和发展,adidas Superstar的意义早已经超越了一双普通篮球鞋,成为潮流文化的一个重要符号。adidas今夏推出的adidas Pro Lux NBA跟它的前辈一样,从运动界直接跨越到了时尚界。     

Using Metallic Coatings to Enhance Thermal Contact Conductance of Electronic Packages

Recently a new thermomechanical model for coated contacts has been developed and shown to be quite accurate. After a brief overview of the theory, this paper concentrates on illustrating the utility of the new model by applying it to a common electronics packaging problem: heat transfer across an aluminum joint. Several soft metallic coatings are considered, and the thermomechanical model is used to predict the improvement in the contact conductance over that for a bare aluminum-to-aluminum joint. For each coating material, heat transfer performance is presented as a function of the coating thickness, the surface roughness, and the applied pressure. Finally, a parameter is proposed that allows candidate coating materials to be ranked.     

AN ENGINEERING METHOD TO EVALUATE THE CRISP TEXTURE OF FRUIT AND VEGETABLES

Precise measurements of the deformation and fracture behaviour of food can be difficult because of problems associated with the produce, for example, sample preparation, gripping, size and geometry. The aim of this study was to characterise fruits and vegetables in terms of fracture properties using an established engineering test method and geometry, the Single-Edge Notched Bend (SENB). The SENB geometry was found to be readily applicable to crisp food produce such as carrots, celery, and apples, which exhibit linear elastic behaviour up to fracture. Fracture toughness and fracture energies were found to be in the range 10–50 kPa m^1/2 and 40–400 Jm⁻², respectively. The structure of these materials was confirmed, using confocal microscopy, and related to the observed fracture behaviour. Cell size and intercellular spaces influenced the values of fracture toughness and fracture energy.